1. Field of the Invention
The present invention relates to a motorized roller formed by accommodating a driving motor and other components in a roller body so that the roller itself is rotatable, and a method for producing the same.
2. Description of Related Art
A motorized roller for use in a device such as a conveyor is conventionally used in various places. Especially, in the case that the roller is used in a place with an extreme temperature swings (such as the vicinity of a refrigerator door), substantial amount of water builds up dew condensation in a cavity of a roller body. Further, the longer the roller body becomes, the larger the cavity becomes, resulting in increased amount of water building up dew condensation in the cavity. The dew condensation in the cavity has harmful effects on a motor or other components within the roller body, causing breakdown and rusting.
Further, when an article is conveyed by a conveyor, the cavity in the roller body increases reverberation caused by collision between the article and the roller. Such noise worsens working conditions.
Reduction of the volume of the cavity in the roller body eliminates such dew condensation and noise. Therefore, the conventional motorized roller has urethane foam filled within the roller body as a filler so as to reduce the cavity in the roller body as much as possible to prevent generation of dew condensation. Having heat insulating properties, urethane foam prevents rapid change in temperature, also helping avoid dew condensation within the roller body in this regard. When the filler is filled in the roller body, the filler having substantially the same outer diameter as the inner diameter of the roller body has been conventionally pressed into the body.
A structure of dew condensation prevention within a roller of a roller conveyor is disclosed in JP 2003-054732A, and a structure of noise prevention for a roller conveyor is disclosed in JP S61-32113U and JP S51-163282U.